gcc/testsuite/gcc.dg/tree-ssa/pr22026.c

   1 /* PR tree-optimization/22026
   2    VRP used think that ~[0,0] + ~[0,0] = ~[0,0], which is wrong.  The
   3    same applies to subtraction and unsigned multiplication.  */
   4
   5 /* { dg-do compile } */
   6 /* { dg-options "-O2 -fdump-tree-vrp1" } */
   7
   8 int
   9 plus (int x, int y)
  10 {
  11   if (x != 0)
  12     if (y != 0)
  13       {
  14         int z = x + y;
  15         if (z != 0)
  16           return 1;
  17       }
  18   return 0;
  19 }
  20
  21 int
  22 minus (int x, int y)
  23 {
  24   if (x != 0)
  25     if (y != 0)
  26       {
  27         int z = x - y;
  28         if (z != 0)
  29           return 1;
  30       }
  31   return 0;
  32 }
  33
  34 int
  35 mult (unsigned x, unsigned y)
  36 {
  37   if (x != 0)
  38     if (y != 0)
  39       {
  40         unsigned z = x * y;
  41         if (z != 0)
  42           return 1;
  43       }
  44   return 0;
  45 }
  46
  47 /* None of the predicates can be folded in these functions.  */
  48 /* { dg-final { scan-tree-dump-times "Folding predicate" 0 "vrp1" } } */